Off-axis light engine parameter determination method, apparatus, device, and storage medium

Abstract

The application relates to the technical field of near-eye display devices, and provides a method and device for determining parameters of an off-axis light engine, equipment and a storage medium, the method comprising the following steps: acquiring an image size of an image projected by a near-eye display device at a conjugate distance and a first coordinate corresponding to a center point of a human eye pupil at a coupling-out area of an optical waveguide; determining a first direction vector group corresponding to light rays of each corner image point and a center image point of the image propagating to the center point of the human eye pupil at the coupling-out area of the optical waveguide based on the first coordinate and the image size; determining a second direction vector group corresponding to projection light rays of the off-axis light engine based on the first direction vector group; and determining parameters of the off-axis light engine based on the second direction vector group, so that a 3D FOV corresponding to the near-eye display device reaches the FOV of the off-axis light engine based on the parameters. The embodiment of the application improves the 3D display effect of the image projected by the near-eye display device, thereby improving the user experience.

Description

Technical Field

[0001] This application relates to the field of near-eye display technology, and in particular to a method, apparatus, device and storage medium for determining the parameters of an off-axis optical engine. Background Technology

[0002] AR (Augmented Reality) glasses can project virtual images into the user's field of vision, achieving perspective and fusion effects, and are applied in various scenarios such as navigation, gaming, education, and healthcare. Currently, at a specific imaging distance other than infinity, the images displayed by the left and right lenses of AR glasses may not be 100% superimposed, resulting in a loss of 3D FOV (field of view), and the 3D display effect needs to be improved. Summary of the Invention

[0003] This application provides a method, apparatus, device, and storage medium for determining off-axis optical engine parameters, aiming to improve the 3D display effect of images projected by near-eye display devices and enhance the user experience.

[0004] To achieve the above objectives, this application provides a method for determining the parameters of an off-axis light engine, applied to a near-eye display device. The off-axis light engine includes a projection lens and a display screen. The method for determining the parameters of the off-axis light engine includes:

[0005] The image size corresponding to the image projected by the near-eye display device at the image-combining distance is obtained, and the first coordinates corresponding to the center point of the human eye pupil at the optical waveguide coupling area of ​​the near-eye display device are obtained;

[0006] Based on the first coordinates and the image size, determine the first direction vector group corresponding to the light rays propagating from each corner image point and the center image point of the image to the center point of the human eye pupil at the optical waveguide coupling area;

[0007] Based on the first direction vector group, determine the second direction vector group corresponding to the projection ray of the off-axis light engine;

[0008] Based on the second direction vector group, the parameters of the off-axis light engine are determined so that the 3D FOV corresponding to the near-eye display device can reach the FOV of the off-axis light engine. The parameters include at least one of the following: the second coordinates corresponding to the intersection of the optical axis of the projection lens and the display screen, and the size of the display screen.

[0009] In addition, to achieve the above objectives, this application also provides an off-axis optical engine parameter determination device, which includes a memory and a processor;

[0010] The memory is used to store computer programs;

[0011] The processor is configured to execute the computer program and, in executing the computer program, implement the steps of the off-axis optical engine parameter determination method as described above.

[0012] In addition, to achieve the above objectives, this application also provides a near-eye display device, the near-eye display device including an off-axis light engine, the parameters of the off-axis light engine being determined by the off-axis light engine parameter determining device as described above, and the 3D FOV corresponding to the near-eye display device reaching the FOV of the off-axis light engine.

[0013] In addition, to achieve the above objectives, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method for determining the parameters of an off-axis optical engine.

[0014] This application discloses a method, apparatus, device, and storage medium for determining the parameters of an off-axis optical engine. By acquiring the image size corresponding to the projected image at the image-to-image distance of a near-eye display device, and the first coordinates corresponding to the center point of the human eye's pupil at the waveguide coupling area of ​​the near-eye display device, a first direction vector group is determined based on the first coordinates and the image size. Then, the first direction vector group corresponding to the light rays propagating from each corner image point and the center image point of the image to the center point of the human eye's pupil at the waveguide coupling area is determined. Based on the first direction vector group, a second direction vector group corresponding to the projected light rays of the off-axis optical engine of the near-eye display device is determined. Finally, based on the second direction vector group, the parameters of the off-axis optical engine (at least one of the second coordinates corresponding to the intersection of the optical axis of the projection lens and the display screen, and the size of the display screen) are determined. This allows the 3D FOV of the near-eye display device to reach the FOV of the off-axis optical engine, solving the 3D FOV loss problem of near-eye display devices, improving the 3D display effect of the projected image, and thus enhancing the user experience. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of AR glasses;

[0017] Figure 2 This is a diagram illustrating the projection of virtual images by AR glasses;

[0018] Figure 3This is a schematic flowchart illustrating the steps of a method for determining off-axis optical engine parameters provided in an embodiment of this application;

[0019] Figure 4 This is a schematic diagram illustrating how light projected from AR glasses through an embodiment of this application combines into a single image in the human eye;

[0020] Figure 5 This is a schematic diagram of an off-axis optical engine provided in an embodiment of this application;

[0021] Figure 6 This is a schematic diagram of the projection of light from AR glasses in three-dimensional space, provided in an embodiment of this application.

[0022] Figure 7 This is a schematic flowchart illustrating the steps for determining the second direction vector group corresponding to the projected light ray of an off-axis optical engine, as provided in an embodiment of this application.

[0023] Figure 8 This is a schematic flowchart illustrating the steps for determining the parameters of an off-axis optical engine, as provided in an embodiment of this application.

[0024] Figure 9 This is a schematic diagram illustrating how the size of a display screen is determined based on the minimum bounding rectangle, according to an embodiment of this application.

[0025] Figure 10 This is a schematic diagram of an off-axis optical engine whose optical axis is not perpendicular to the display screen plane, provided in an embodiment of this application;

[0026] Figure 11 This is a schematic block diagram of an off-axis optical engine parameter determination device provided in an embodiment of this application. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the described order. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0029] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0030] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0031] AR glasses are electronic devices that can overlay and display real-world scenes and virtual images, such as... Figure 1 As shown, the structure of AR glasses is similar to that of ordinary glasses, both having lenses, frames, temples, and nose pads. The lenses of AR glasses are transparent, allowing users to clearly see the external environment. In addition, AR glasses can project virtual images to be displayed, enabling users to see both the real-world scene and the virtual image simultaneously.

[0032] Currently, at a specific image-matching distance d (not infinite), the images displayed by the left and right lenses of AR glasses cannot be 100% perfectly superimposed, resulting in a loss of 3D FOV. Figure 2 As shown. Figure 2 The AR glasses consist of left and right eye waveguides and corresponding projection light engines (PL and PR) for the left and right eyes. VL and VR are two cameras placed in specific positions to simulate human eye imaging. Based on the display principle of diffractive waveguides, the light rays projected by PL / PR and received by VL / VR are rotated 180 degrees about an axis n1 / n2 perpendicular to the waveguide surface. The FOV of the image received by VL / VR is equal to the FOV of the image projected by PL / PR, both denoted by θ. Figure 2 As can be seen, when the image-combining distance d is determined, on the plane at a distance d in front of the user, the images ImgL and ImgR seen by the user's left and right eyes cannot completely overlap; only the middle portion of the image can overlap. Therefore, only within this portion of the FOV can binocular stereoscopic vision be formed, which is referred to as the 3D FOV region. Figure 2 The pink area in the middle reflects the 3D FOV area of ​​each eye, at an angle of α.

[0033] from Figure 2 It is evident that α < θ, meaning that the 3D FOV of the displayed image is smaller than the FOV of the light engine. AR glasses suffer from 3D FOV loss and cannot fully utilize the pixels of the projection light engine display to achieve 3D display.

[0034] To address the aforementioned issues, embodiments of this application provide a method, apparatus, device, and storage medium for determining off-axis optical engine parameters, which aims to resolve the 3D FOV loss problem in near-eye display devices, improve the 3D display effect of projected images from near-eye display devices, and enhance the user experience.

[0035] Please see Figure 3 , Figure 3 This is a schematic flowchart illustrating a method for determining off-axis optical engine parameters according to an embodiment of this application. This method can be applied to near-eye display devices or to electronic devices including an off-axis optical engine parameter determination device. This application does not specifically limit the application scenarios of this off-axis optical engine parameter determination method. Near-eye display devices include, but are not limited to, AR glasses, VR (Virtual Reality) glasses, and other similar devices.

[0036] like Figure 3 As shown, the method for determining the parameters of the off-axis optical engine in this application specifically includes steps S101 to S104.

[0037] S101. Obtain the image size corresponding to the image projected by the near-eye display device at the image-combining distance, and obtain the first coordinates corresponding to the center point of the human eye pupil at the optical waveguide coupling area of ​​the near-eye display device.

[0038] For example, taking AR glasses as a near-eye display device, AR glasses include components such as lenses, frames, temples, nose pads, left and right eye waveguides, and an off-axis light engine. The off-axis light engine includes a projection lens, a display screen, and a mechanical support structure. The display screen can use micro-LED (micro-Light-Emitting Diode) or micro-OLED.

[0039] (micro-Organic Light-Emitting Diode), LCOS (Liquid Crystal On Silicon),

[0040] Liquid crystal coated with silicon (LCC), DLP (Digital Light Processing), etc.

[0041] For example, such as Figure 4As shown, the AR glasses include left and right eye waveguides and off-axis optical engines P1 / P2. The frame and temples are not shown in the diagram. V1 / V2 are two cameras used to simulate human eye imaging, and s is the interpupillary distance. Based on the display principle of diffractive waveguides, the light rays projected by the off-axis optical engines P1 / P2 and the same light rays received by the cameras V1 / V2 are rotated 180 degrees about axes n1 / n2 perpendicular to the waveguide surface (axes n1 and n2 are known quantities). The FOV of the image received by V1 / V2 is equal to the FOV of the image projected by P1 / P2, which is θ.

[0042] like Figure 5 As shown, Figure 5 This is a 3D schematic diagram of the off-axis light engine, which includes a projection lens, a display screen, and a mechanical support structure (not shown in the diagram). The optical center of the projection lens is denoted as c, and the focal length of the projection lens is f. The optical axis of the off-axis light engine is perpendicular to the plane of its internal display screen, and the intersection point m of the optical axis of the off-axis light engine and the internal display screen does not coincide with the center point o' of the display screen.

[0043] Since the display process and imaging principle of the left and right lenses of AR glasses are the same, this article will only take one lens (such as the left lens) as an example to introduce the method for determining the parameters of the off-axis optical engine.

[0044] like Figure 6 As shown, Figure 6 The image represents a portion of the light rays projected by the AR glasses in three-dimensional space. The rectangle formed by q1, q2, q3, and q4 represents the image area displayed on plane W at the image convergence distance d. For the left lens, the rectangular area formed by q1, q2, q3, and q4 is the corresponding projected image area of ​​the left lens. The center image point of the projected image is denoted as o, and q1, q2, q3, and q4 are the image points at each corner of the projected image, i.e., the image points at each edge of the projected image. The image size corresponding to the projected image of the AR glasses at the image convergence distance d is obtained, which is also the size of the rectangular area formed by q1, q2, q3, and q4.

[0045] The center point of the human eye's pupil at the optical waveguide coupling region is denoted as c', which is... Figure 4 The optical center of the camera V1 is used to obtain the coordinates of the center point c' of the human eye's pupil at the optical waveguide coupling area. For ease of distinction and description, the coordinates of the center point c' of the human eye's pupil at the optical waveguide coupling area will be referred to as the first coordinates below.

[0046] S102. Based on the first coordinates and the image size, determine the first direction vector group corresponding to the light rays propagating from each corner image point and the center image point of the image to the center point of the human eye pupil at the optical waveguide coupling area.

[0047] Once the image-combination distance d and the image size corresponding to the projected image at the image-combination distance d are determined, the vectors of the light rays propagating from the four corner image points q1, q2, q3, q4 and the central image point o to the center point c' of the human eye's pupil at the optical waveguide coupling area can be obtained. and and Form the first direction vector group.

[0048] S103. Based on the first direction vector group, determine the second direction vector group corresponding to the projection light of the off-axis light engine.

[0049] Since the light rays projected by the off-axis optical engine and the same light rays received by the camera are rotated 180 degrees about the axis perpendicular to the waveguide surface, the imaging light rays can be analyzed based on their respective directional vectors. and Calculate the reverse vector of the projected light rays inside the off-axis light engine, that is... Figure 5 As shown and and Form the second direction vector group.

[0050] In some embodiments, such as Figure 7 As shown, step S103 may include sub-step S1031 and sub-step S1032.

[0051] S1031. Determine a rotation matrix for rotating 180 degrees around an axis perpendicular to the optical waveguide;

[0052] S1032. Multiply each direction vector in the first direction vector group by the rotation matrix to obtain each direction vector in the corresponding second direction vector group.

[0053] For example, the rotation matrix for rotating the waveguide by 180 degrees around an axis n1 perpendicular to the waveguide is obtained, denoted as Rn1(π). The calculation yields...

[0054] S104. Based on the second direction vector group, determine the parameters of the off-axis light engine, so as to achieve the FOV of the 3D FOV corresponding to the near-eye display device to the FOV of the off-axis light engine based on the parameters, wherein the parameters include at least one of the second coordinates corresponding to the intersection of the optical axis of the projection lens and the display screen, and the size of the display screen.

[0055] For example, by and The coordinates of the intersection point m between the optical axis of the off-axis light engine projection lens and the display screen, as well as the size of the off-axis light engine display screen, are calculated. For ease of description, the coordinates of the intersection point m will be referred to as the second coordinates below.

[0056] In some embodiments, such as Figure 8 As shown, step S104 may include sub-steps S1041 to S1043.

[0057] S1041. Determine the plane equation of the plane corresponding to the display screen;

[0058] S1042. Determine the coordinates of the intersection points of each direction vector and the plane based on each direction vector in the second direction vector group and the plane equation;

[0059] S1043. Based on the coordinates of each of the intersection points, determine the parameters of the off-axis optical engine.

[0060] For example, the plane equation of the plane corresponding to the display screen is determined based on the focal length f and rotation matrix Rn1(π) of the projection lens of the off-axis light engine.

[0061] In some embodiments, determining the plane equation corresponding to the display screen includes: obtaining the focal length of the projection lens and determining a rotation matrix that rotates 180 degrees around an axis perpendicular to the optical waveguide; based on the focal length, the rotation matrix, and a first direction vector in the first direction vector group, determining the plane equation as Ax + By + Cz + D = 0, where the first direction vector is the direction vector corresponding to the light ray propagating from the center image point to the first position; wherein, [A, B, C] is the unit vector obtained by multiplying the rotation matrix by the first direction vector, and D is the focal length.

[0062] That is, the direction vectors in the first direction vector group Let be the first direction vector, and calculate. The corresponding unit vector, denoted as [A, B, C], gives the plane equation of the plane corresponding to the display screen as Ax + By + Cz + D = 0, where the specific value of D is the focal length f of the projection lens.

[0063] After obtaining the plane equation Ax + By + Cz + D = 0 corresponding to the display screen, based on and The equation of the plane, Ax + By + Cz + D = 0, can be calculated. and The coordinates of the intersection point with the plane corresponding to the display screen, for example, such as Figure 5 The coordinates of points q1′, q2′, q3′, q4′ and m are shown in the figure.

[0064] In some embodiments, determining the coordinates of the intersection points of each direction vector and the plane based on each direction vector in the second direction vector group and the plane equation includes:

[0065] According to the formula Calculate the coordinates of each of the intersection points; where (x0, y0, z0) are the coordinates corresponding to the optical center of the projection lens, (m, n, p) are the unit vectors corresponding to any direction vector in the second direction vector group, and (x, y, z) are the coordinates of the intersection point of any direction vector with the plane.

[0066] For example, the coordinates (x0, y0, z0) corresponding to the optical center c of the projection lens can be (0, 0, 0).

[0067] If determined The corresponding unit vector is (m1, n1, p1), then we can calculate... The coordinates of the intersection point q1′ with the plane corresponding to the display screen are (x1, y1, z1):

[0068]

[0069] If determined The corresponding unit vector is (m2, n2, p2), then we can calculate... The coordinates of the intersection point q2′ with the plane corresponding to the display screen are (x2, y2, z2):

[0070]

[0071] If determined The corresponding unit vector is (m3, n3, p3), then we can calculate... The coordinates of the intersection point q3′ with the plane corresponding to the display screen are (x3, y3, z3):

[0072]

[0073] If determined The corresponding unit vector is (m4, n4, p4), then we can calculate... The coordinates of the intersection point q4′ with the plane corresponding to the display screen are (x4, y4, z4):

[0074]

[0075] If determined The corresponding unit vector is (m5, n5, p5), which can then be calculated. The coordinates of the intersection point m with the plane corresponding to the display screen are (x5, y5, z5):

[0076]

[0077] In some embodiments, determining the parameters of the off-axis light engine based on the coordinates of each of the intersection points includes: determining the size of the display screen according to the coordinates of each corner point of the display screen.

[0078] For example, will The intersection points q1′, q2′, q3′, and q4′ with the plane corresponding to the display screen are taken as the corner points of the display screen. After obtaining the coordinates of q1′, q2′, q3′, and q4′, the size of the display screen is determined based on the coordinates of q1′, q2′, q3′, and q4′.

[0079] In some embodiments, each corner point of the display screen includes a first corner point, a second corner point, a third corner point, and a fourth corner point. Determining the size of the display screen based on the coordinates corresponding to each corner point includes: determining the corresponding minimum bounding rectangle based on the coordinates of the first corner point, the second corner point, the third corner point, and the fourth corner point; and determining the size of the minimum bounding rectangle as the size of the display screen.

[0080] For example, such as Figure 9 As shown, the minimum bounding rectangle of points q1′, q2′, q3′, and q4′ within the corresponding plane of the display screen is calculated. The size of this minimum bounding rectangle is the actual minimum size required for the display screen. It can be understood that the size of the display screen can be larger than this minimum bounding rectangle size.

[0081] After setting the second coordinate corresponding to the intersection point m of the optical axis of the projection lens and the display screen, and the size of the display screen, the 3D FOV of the AR glasses can reach the FOV of the off-axis light engine.

[0082] like Figure 4 As shown, on plane W at the image convergence distance d, the images ImgL (thick blue line) and ImgR (thick yellow line) seen by the user's left and right eyes completely overlap. Therefore, the off-axis optical engine can form a binocular stereo image throughout the entire field of view. Figure 4 The pink area in the middle reflects the 3D FOV area seen by the left eye, with an angle α = θ. Therefore, the 3D FOV is equal to the FOV of the off-axis light engine, and the display pixels of the off-axis light engine are fully utilized.

[0083] In the above embodiments, the optical axis of the off-axis optical engine is perpendicular to the plane of its internal display screen. In other embodiments, the optical axis of the off-axis optical engine may not be perpendicular to the plane of the display screen, for example, as... Figure 10 As shown, this design introduces more degrees of freedom for optimization, which is beneficial for achieving better projection effects in the light engine design.

[0084] In this application, by obtaining the image size corresponding to the projected image at the image-combining distance of the near-eye display device, and the first coordinate corresponding to the center point of the human eye's pupil at the waveguide coupling area of ​​the near-eye display device, a first direction vector group corresponding to the light rays propagating from each corner image point and the center image point of the image to the center point of the human eye's pupil at the waveguide coupling area is determined based on the first coordinate and the image size. Based on the first direction vector group, a second direction vector group corresponding to the projection light rays of the off-axis optical engine of the near-eye display device is determined. Then, based on the second direction vector group, the parameters of the off-axis optical engine (at least one of the second coordinate corresponding to the intersection of the optical axis of the projection lens and the display screen, and the size of the display screen) are determined. Based on the parameters, the 3D FOV of the near-eye display device reaches the FOV of the off-axis optical engine, solving the 3D FOV loss problem of the near-eye display device, improving the 3D display effect of the projected image of the near-eye display device, and thus enhancing the user experience.

[0085] Please see Figure 11 , Figure 11 This is a schematic block diagram of an off-axis optical engine parameter determination device provided in an embodiment of this application. The off-axis optical engine parameter determination device can be disposed in a near-eye display device and is used to perform the aforementioned off-axis optical engine parameter determination method.

[0086] like Figure 11 As shown, the off-axis optical engine parameter determination device 300 may include a processor 310 and a memory 320, wherein the processor 310 and the memory 320 are connected via a bus, such as an I2C (Inter-integrated Circuit) bus.

[0087] Specifically, the processor 310 can be a microcontroller unit (MCU), a central processing unit (CPU), or a digital signal processor (DSP), etc.

[0088] Specifically, the memory 320 can be a Flash chip, a read-only memory (ROM) disk, an optical disk, a USB flash drive, or a portable hard drive, etc. The memory 320 stores various computer programs for the processor 310 to execute.

[0089] The processor 310 is configured to run a computer program stored in the memory, and to perform the following steps when executing the computer program:

[0090] The image size corresponding to the image projected by the near-eye display device at the image-combining distance is obtained, and the first coordinates corresponding to the center point of the human eye pupil at the optical waveguide coupling area of ​​the near-eye display device are obtained;

[0091] Based on the first coordinates and the image size, determine the first direction vector group corresponding to the light rays propagating from each corner image point and the center image point of the image to the center point of the human eye pupil at the optical waveguide coupling area;

[0092] Based on the first direction vector group, determine the second direction vector group corresponding to the projection ray of the off-axis light engine;

[0093] Based on the second direction vector group, the parameters of the off-axis light engine are determined so that the 3D FOV corresponding to the near-eye display device can reach the FOV of the off-axis light engine. The parameters include at least one of the following: the second coordinates corresponding to the intersection of the optical axis of the projection lens and the display screen, and the size of the display screen.

[0094] In some embodiments, when the processor 310 determines the parameters of the off-axis optical engine based on the second direction vector group, it is configured to:

[0095] Determine the plane equation of the plane corresponding to the display screen;

[0096] Based on each direction vector in the second direction vector group and the plane equation, determine the coordinates of the intersection points of each direction vector and the plane;

[0097] The parameters of the off-axis optical engine are determined based on the coordinates of each of the intersection points.

[0098] In some embodiments, when implementing the plane equation for determining the plane corresponding to the display screen, the processor 310 is configured to:

[0099] Obtain the focal length of the projection lens and determine the rotation matrix for rotating 180 degrees around an axis perpendicular to the optical waveguide;

[0100] Based on the focal length, the rotation matrix, and the first direction vector in the first direction vector group, the plane equation is determined to be Ax+By+Cz+D=0, and the first direction vector is the direction vector corresponding to the light ray propagating from the central image point to the first position;

[0101] Where [A, B, C] is the unit vector of the rotation matrix multiplied by the first direction vector, and D is the focal length.

[0102] In some embodiments, when the processor 310 determines the coordinates of the intersection points of each direction vector and the plane based on each direction vector in the second direction vector group and the plane equation, it is configured to:

[0103] According to the formula Calculate the coordinates of each of the intersection points;

[0104] Where (x0, y0, z0) are the coordinates of the optical center of the projection lens, (m, n, p) are the unit vectors corresponding to any direction vector in the second direction vector group, and (x, y, z) are the coordinates of the intersection point of any direction vector and the plane.

[0105] In some embodiments, the intersection points of each direction vector in the second direction vector group with the plane include each corner point of the display screen. When the processor 310 determines the parameters of the off-axis light engine based on the coordinates of each intersection point, it is configured to:

[0106] The size of the display screen is determined based on the coordinates of each corner point of the display screen.

[0107] In some embodiments, the corner points of the display screen include a first corner point, a second corner point, a third corner point, and a fourth corner point. When the processor 310 determines the size of the display screen based on the coordinates corresponding to each corner point, it is configured to:

[0108] Determine the corresponding minimum bounding rectangle based on the coordinates of the first corner point, the second corner point, the third corner point, and the fourth corner point;

[0109] The size of the minimum bounding rectangle is determined as the size of the display screen.

[0110] In some embodiments, when the processor 310 determines the second direction vector group corresponding to the projection ray of the off-axis light engine based on the first direction vector group, it is configured to:

[0111] Determine the rotation matrix for rotating 180 degrees around an axis perpendicular to the optical waveguide;

[0112] Each direction vector in the first direction vector group is multiplied by the rotation matrix to obtain each direction vector in the corresponding second direction vector group.

[0113] The off-axis optical engine parameter determination device 300 can execute the off-axis optical engine parameter determination method provided in the embodiments of this application. Therefore, it can achieve the beneficial effects that the off-axis optical engine parameter determination method provided in the embodiments of this application can achieve. For details, please refer to the previous embodiments, which will not be repeated here.

[0114] This application embodiment also provides a near-eye display device, which includes, but is not limited to, AR glasses, VR glasses, and other devices. The near-eye display device includes an off-axis light engine, wherein the off-axis light engine includes a projection lens and a display screen, and the parameters of the off-axis light engine are determined by an off-axis light engine parameter determining device. For example, the off-axis light engine parameter determining device can be... Figure 11 The off-axis optical engine parameter determination device 300 is shown. When the near-eye display device uses this off-axis optical engine, the 3D FOV of the near-eye display device reaches the FOV of the off-axis optical engine. Therefore, the beneficial effects of the off-axis optical engine parameter determination method provided in the embodiments of this application can be achieved, as detailed in the preceding embodiments, and will not be repeated here.

[0115] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the off-axis optical engine parameter determination method described above.

[0116] The computer-readable storage medium can be an internal storage unit of the off-axis optical engine parameter determination device or the near-eye display device described in the foregoing embodiments, such as a hard disk or memory of the off-axis optical engine parameter determination device or the near-eye display device. The computer-readable storage medium can also be an external storage device of the off-axis optical engine parameter determination device or the near-eye display device, such as a pluggable hard disk, Smart Media Card (SMC), Secure Digital Card (SDCard), Flash Card, etc., equipped on the off-axis optical engine parameter determination device or the near-eye display device.

[0117] Since the computer program stored in the storage medium can execute any of the off-axis optical engine parameter determination methods provided in the embodiments of this application, the beneficial effects that any of the off-axis optical engine parameter determination methods provided in the embodiments of this application can achieve can be realized. For details, please refer to the previous embodiments, which will not be repeated here.

[0118] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0119] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application.

Claims

1. A method for determining the parameters of an off-axis optical engine, characterized in that, The off-axis light engine includes a projection lens and a display screen, and the method for determining the parameters of the off-axis light engine includes: The image size corresponding to the image projected by the near-eye display device at the image-combining distance is obtained, and the first coordinates corresponding to the center point of the human eye pupil at the optical waveguide coupling area of ​​the near-eye display device are obtained; Based on the first coordinates and the image size, determine the first direction vector group corresponding to the light rays propagating from each corner image point and the center image point of the image to the center point of the human eye pupil at the optical waveguide coupling area; Based on the first direction vector group, a second direction vector group corresponding to the projection ray of the off-axis optical engine is determined; the second direction vector group and the first direction vector group are rotated 180 degrees about the axis perpendicular to the optical waveguide; Based on the second direction vector group, the parameters of the off-axis light engine are determined so that the 3D field of view (FOV) of the near-eye display device can reach the FOV of the off-axis light engine. The parameters include at least one of the following: the second coordinates corresponding to the intersection of the optical axis of the projection lens and the display screen, and the size of the display screen. Determining the parameters of the off-axis optical engine based on the second direction vector group includes: Based on the focal length of the projection lens and the rotation matrix that rotates 180 degrees around an axis perpendicular to the optical waveguide, the plane equation of the plane corresponding to the display screen is determined. Based on each direction vector in the second direction vector group and the plane equation, determine the coordinates of the intersection points of each direction vector and the plane; The parameters of the off-axis optical engine are determined based on the coordinates of each of the intersection points.

2. The method for determining the parameters of an off-axis optical engine as described in claim 1, characterized in that, Determining the plane equation corresponding to the display screen includes: Based on the focal length, the rotation matrix, and the first direction vector in the first direction vector group, the plane equation is determined to be Ax+By+Cz+D=0, where the first direction vector is the direction vector corresponding to the light ray propagating from the central image point to the first position; the first position represents the center point of the human eye pupil at the optical waveguide coupling area. Where [A, B, C] is the unit vector of the rotation matrix multiplied by the first direction vector, and D is the focal length.

3. The method for determining the parameters of an off-axis optical engine as described in claim 1, characterized in that, Determining the coordinates of the intersection points of each direction vector and the plane based on each direction vector in the second direction vector group and the plane equation includes: According to the formula (m, n, p), calculate the coordinates of each of the intersection points; in,( Let (m, n, p) be the coordinates corresponding to the optical center of the projection lens, and let (m, n, p) be the unit vector corresponding to any direction vector in the second direction vector group. The coordinates are the points where the intersection of any direction vector and the plane is located.

4. The method for determining the parameters of an off-axis optical engine as described in claim 1, characterized in that, The intersection points of each direction vector in the second direction vector group with the plane include each corner point of the display screen. Determining the parameters of the off-axis light engine based on the coordinates of each intersection point includes: The size of the display screen is determined based on the coordinates of each corner point of the display screen.

5. The method for determining the parameters of an off-axis optical engine as described in claim 4, characterized in that, The display screen includes a first corner point, a second corner point, a third corner point, and a fourth corner point. Determining the size of the display screen based on the coordinates corresponding to each corner point includes: Determine the corresponding minimum bounding rectangle based on the coordinates of the first corner point, the second corner point, the third corner point, and the fourth corner point; The size of the minimum bounding rectangle is determined as the size of the display screen.

6. The method for determining the parameters of an off-axis optical engine as described in any one of claims 1 to 5, characterized in that, The step of determining the second direction vector group corresponding to the projection ray of the off-axis optical engine based on the first direction vector group includes: Determine the rotation matrix for rotating 180 degrees around an axis perpendicular to the optical waveguide; Each direction vector in the first direction vector group is multiplied by the rotation matrix to obtain each direction vector in the corresponding second direction vector group.

7. A device for determining the parameters of an off-axis optical engine, characterized in that, The off-axis optical engine parameter determination device includes a memory and a processor; The memory is used to store computer programs; The processor is configured to execute the computer program and, in executing the computer program, implement the steps of the method for determining the off-axis optical engine parameters as described in any one of claims 1 to 6.

8. A near-eye display device, characterized in that, The near-eye display device includes an off-axis light engine, the parameters of which are determined by the apparatus as described in claim 7, and the 3D FOV of the near-eye display device reaches the FOV of the off-axis light engine.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method for determining the parameters of an off-axis optical engine as described in any one of claims 1 to 6.

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